A gun shop in Tucson has canceled an effort by retired astronaut Mark Kelly, an outspoken gun control advocate, to buy a semi-automatic rifle as a way of demonstrating how easy it is to buy powerful weapons.

Kelly, the husband of former Rep. Gabrielle Giffords, who was one of the targets of a mass shooting near Tucson on Jan. 8, 2011, had sought to purchase the Sig Sauer M400, a variant of the AR-15 to demonstrate how easy or hard it would be to buy such a rifle.

But Kelly's purchase has been rescinded, according to Doug MacKinlay, owner of Diamondback Police Supply. MacKinlay was not immediately available by telephone, but he announced the cancellation in a Facebook posting.

"While I support and respect Mark Kelly's Second Amendment rights to purchase, possess, and use firearms in a safe and responsible manner, his recent statements to the media made it clear that his intent in purchasing the Sig Sauer M400 5.56mm rifle from us was for reasons other than for his personal use. In light of this fact, I determined that it was in my company's best interest to terminate this transaction prior to his returning to my store to complete the Federal Form 4473 and NICS (National Instant Criminal Background Check System) background check required of Mr. Kelly before he could take possession of this firearm. A full refund was sent to Mr. Kelly, via express mail, on Thursday of last week."

Missy Franklin, Jenny Simpson, Adeline Gray and three other Colorado women could be big players at the 2016 Rio OlympicsWhen people ask Missy Franklin for her thoughts about the Summer Olympics that will begin a year from Wednesday in Rio de Janeiro, she hangs a warning label on her answer.